The JUpiter ICy moons Explorer (JUICE) is a European Space Agency (ESA) mission to make multiple flybys of Jupiter's satellites Ganymede, Callisto, and Europa and then to go into orbit around Ganymede.

The science goals focus on Jupiter and its system, with particular emphasis on Ganymede as a planetary body and potential habitat.

The primary science objectives for Ganymede (most of these apply to Callisto as well) are: characterization of the ocean layers and detection of putative subsurface water reservoirs; topographical, geological, and compositional mapping of the surface; study of the physical properties of the icy crusts; characterization of the internal mass distribution, dynamics and evolution of the interiors; investigation of the exosphere; and study of Ganymede's intrinsic magnetic field and its interactions with the Jovian magnetosphere.

For Europa, the focus is on the chemistry essential to life, including organic molecules, and on understanding the formation of surface features and the composition of the non-water-ice material.

NASA is partnering with ESA for the JUICE mission and will provide instruments and components for the spacecraft.

By studying Jupiter and its moons, JUICE will help astrobiologists understand how habitable worlds might emerge around gas giant planets. The icy moons of Jupiter are also primary targets for astrobiology research in the Solar System. Moons like Europa are believed to harbor oceans of liquid water beneath their icy surfaces, and it is possible that these oceans could be habitable for life as we know it.

NASA will provide the Ultraviolet Spectrograph (UVS) for the JUICE mission, as well as subsystems and components for two additional instruments: the Particle Environment Package (PEP) and the Radar for Icy Moon Exploration (RIME) experiment.

Mission Profile

JUICE is scheduled to be launched on 13 April 2023 at 12:15 UTC (8:15 a.m. EDT) on an Ariane 5 from the European Spaceport in Kourou, French Guiana. After a 7 to 8-year cruise to Jupiter, utilizing Earth and Venus gravity assists, JUICE will go into orbit around Jupiter in 2031.

The spacecraft will use flybys of Ganymede and Callisto to optimize the orbit. This will include flybys of Europa. These orbits will be used to study Jupiter and its moons, and then it will be inserted into a highly elliptical orbit around Ganymede. The orbit will evolve to a 5000 km circular orbit, and will be lowered into a 500 km circular orbit. After mapping and other investigations at this altitude, it will lowered again to a 200 km circular orbit.

The nominal mission ends after about 3 years, there is the possibility of an extension to the mission of 200 or more days. In either case, the mission will end with an impact on the surface of Ganymede.

Spacecraft and Subsystems

The spacecraft is still in the development stage, but it will be powered by a large bank (60 - 75 square meters) of solar arrays employing GaAs solar cells optimized for low-intensity / low-temperature conditions. About 3000 kg of chemical propellant will be required for orbit insertions and maneuvers. Communications will be primarily via a ~3-meter diameter high-gain antenna, both X- and K-band will be used.

Radiation shielding will be used to protect onboard electronics from the Jovian environment.

The JUICE science payload will include the JANUS camera system, the MAJIS visible and infrared imaging spectrometer, the UVS ultraviolet imaging spectrograph, RIME radar sounder, GALA laser altimeter, SWI submillimeter wave instrument, J-MAG magnetometer, PEP particle and plasma package, RPWI radio and plasma wave investigation, 3GM radio science package, and the PRIDE radio science instrument.

Caption courtesy of NASA

Meet the European Space Agency's heavy-lift, workhorse rocket.

Ariane 5 is operated by Arianespace and carries a per launch price tag of approximately $168 million (USD). However, Arianespace offers ride-shares for two large payloads on the same mission.

Stats

Height: 46–52 m (151–171 ft)

Diameter: 5.4 m (18 ft)

Mass: 777,000 kg (1,713,000 lb)

Stages: 2

The two payloads ride one on top of the other, with the upper payload customer paying $101 million (USD) and the lower payload customer paying $67 million (USD).

This makes the price of an Ariane 5 launch competitive with other heavy-lift rockets from a "what the customer pays" perspective.

Ariane 5 debuted on June 4th, 1996, and has undergone five upgrades over the years.

Of those five variants, one remains in operation: the Ariane 5 ECA (Evolution Cryotechnique type A).

Over its service life, the rocket has launched hundreds of satellites as well as five cargo resupply missions to the International Space Station.

Arianespace and the European Space Agency are in the process of building Ariane 5's successor, Ariane 6, which will be more affordable than Ariane 5.

At this time, the rocket will fly until at least 2023.

Photo: An Ariane 5 lifts off from South America. Credit: Arianespace

ELA-3 (Ensemble de Lancement Ariane 3) is a launch pad built specially for the Ariane 5 rocket - the European Space Agency's (ESA's) and Arianespace's heavy-lift workhorse.

Built in the mid-1990s, it was first used on June 4th, 1996, for the maiden launch of Ariane 5.

ELA-3 is located in the Guiana Space Centre (French: Centre Spatial Guyanais), a French and European spaceport located near Kourou in French Guiana near the northern tip of South America.

The space centre itself has been operational since 1968 and has hosted launches for the ESA, the French National Centre for Space Studies, and commercial companies Arianespace and Azercosmos.

A total of 9 different rockets types have launched from the Guiana Space Centre, including three active rockets and six retired vehicles.

The current rocket fleet at the space center is comprised of the Ariane 5 for heavy payloads, the Russian-provided Soyuz 2.1 for medium-mass payloads, and Vega for smaller satellites.

Jupiter is the archetype for the giant planets of the Solar System and for the numerous giant planets now known to orbit other stars. Moreover, Jupiter's diverse Galilean satellites - three of which are believed to harbor internal oceans - are central to understanding the habitability of icy worlds.

Understanding the Jovian system and unraveling its history, from its origin to the possible emergence of habitable environments, will give us a better insight into how gas giant planets and their satellites form and evolve. In addition, new light should be shed on the potential for the emergence of life in Jupiter-like exoplanetary systems.

The JUICE mission will address two themes of ESA's Cosmic Vision program: What are the conditions for planet formation and the emergence of life? and How does the Solar System work?

The focus of JUICE is to characterize the conditions that may have led to the emergence of habitable environments among the Jovian icy satellites, with special emphasis on the three ocean-bearing worlds, Ganymede, Europa, and Callisto.

Ganymede is identified for detailed investigation since it provides a natural laboratory for analysis of the nature, evolution and potential habitability of icy worlds in general, but also because of the role it plays within the system of Galilean satellites, and its unique magnetic and plasma interactions with the surrounding Jovian environment.

For Europa, the focus is on the chemistry essential to life, including organic molecules, and on understanding the formation of surface features and the composition of the non-water-ice material. Furthermore, JUICE will provide the first subsurface sounding of the moon, including the first determination of the minimal thickness of the icy crust over the most recently active regions.

The mission will also focus on characterizing the diversity of processes in the Jupiter system which may be required in order to provide a stable environment at Ganymede, Europa, and Callisto on geologic time scales.

The studies of the Jovian atmosphere will be focused on the investigation of its structure, dynamics, and composition. The circulation, meteorology, chemistry, and structure of Jupiter will be studied from the cloud tops to the thermosphere. These observations will be attained over a sufficiently long temporal baseline with broad latitudinal coverage to investigate evolving weather systems and the mechanisms of transporting energy, momentum and material between the different layers.

Caption courtesy of the ESA